\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{patterns}
\begin{document}
\footnotesize
  \begin{tikzpicture}[>=stealth]
    \draw[thick](-1.25,-0.16)rectangle++(2.5,0.08);
    \draw[thick](-1.5,-0.08)rectangle++(3,0.08)(-2.5,0)--(2.5,0);
    \draw[thin](-2.5,-0.1)--++(0,1.2)--++(30:0.1)--++(150:0.2)--++(30:0.1)--++(0,1.2)--++(2.4,0)--++(60:0.1)--++(-60:0.2)--++(60:0.1)--++(2.4,0)--++(0,-1.2)--++(210:0.1)--++(-30:0.2)--++(210:0.1)--++(0,-1.2);
    \foreach \x in{-1,0,1} 
      {
        \draw[thin](\x,-0.2)--++(0,-0.35);
        \draw[thick](\x-0.04,0.2)--++(0.08,0)--++(0.1,1.5)--++(-0.08,0)--cycle;
      }
    \draw[thick](-1.15,1.7)rectangle++(2.5,0.1);
    \foreach \x in{-1,0} {\draw[thin,<->](\x,-0.45)--++(1,0)node[midway,above]{$s$}; }
    \draw[thin](-0.94,1.85)--++(0,0.3)(-1.04,0.25)--++(0,1.9)(-1.1,0.2)--++(-1,0);
    \draw[thin,<-](-1.9,0.2)--++(0,0.3)node[midway,above,sloped]{$\Delta$};
    \draw[thin,->](-1.9,-0.2)--++(0,0.2);
    \draw[thin,->](-1.34,2.0)--++(0.3,0)node[midway,above,sloped]{$f$};
    \draw[thin,->](-0.74,2.0)--++(-0.2,0);
  \end{tikzpicture}
\end{document}